Research On Parameters And Application Of Gas Metal Arc Additive Manufacturing

Gas metal arc additive manufacturing is a 3D printing technology using welding arc to deposit wire, fabricating metal parts by layers. Recently, most of the researches in this area focused on the technology parameters and the microstructure, little has been done in materials we used. This paper focuses on the flux-cored wire of GMA-AM and the process characteristics, with an aim of fabricating different models. Therefore, this paper has an important worth of theory and application.The 3D-Printing platform has been integrated by KUKA robot and Fronius CMT-4000 i.The platform can directly identifies STL document and generated machining path. Through this way a direct connection between models to parts has been established.A high-alloy flux-cored wire, which has a good forming performance and has a welding spatter as low as 2%, has been developed. The microstructure of the deposited metal is mainly composed of lath martensite. The hardness of deposited metal in welded condition is greater than 42 HRC, which can soar up to 45 HRC after a temperature tempering at 500?. The tensile strength of the deposited metal is higher than 1000 MPa. Meanwhile, the bonding strength between deposited metal to substrate is higher than 600 MPa. Thus, the flux-cored wire can fully meet the requirements.Based on a series of orthogonal experiments about current, voltage and speed, we get these results fowling: Multi-pass weld width is independent with print layers, but strongly related to the deposition rate which showing a negative correlation; the parts height increase substantially in a stable deposition rate; with the voltage increases.Finally, using the parameters and the wire of GMA-AM below, a series of typical parts such as cylindrical member, solid cube, gear of tank driving wheel and driven wheel have successfully been produced. The technology of repair has also been discussed. Through the metallurgical test and the mechanical test, the performances and sizes of the parts can completely meet the requirements.